Single Chip, 24V, control IC replacing Relay logic


Thread Starter



I'm working for a large antenna project. For the same, I want to replace old relay logic by simple, small-size alternative.

Please suggest me simple, easy to troubleshoot single device / IC that has:

*10 to 15 I/O pins with states 24V= T, 0V= F.
*Single IC, easy to troubleshoot by unskilled workers.

I have an option of using a uC with SSR or a single chip. I don't want to use uC with SSR.
To answer your question directly: A AVR microcontroller is programmable by C and can be programmed and plopped on a protoboard into a socket with essentially one chip and a bypass capacitor. You can also do in circuit programmability. I'd recommend opto couplers to go from your 5V digital logic to 24VIO as it will isolate your CPU from the outside world, at least with respect to the power supplies. So you'd need the uC, some optos, some resistors, a power regulator and/or DC supply, and some connectors.

Another [probably more acceptable] answer I'd give is to use a 24V brick PLC from Keyence, automation direct, etc. Just about everyone has a version of these things, so go with the one you are most familiar with. If yu want something easy to troubleshoot these are pretty bulletproof and the software is rather simple.


curt wuollet

Probably not a chip, trends are away from high supply voltage chips. So you would need SSRs or relays. But it seems like an ideal application for a one piece PLC like the Click or similar. And it would be much easier to program and has real world input protection and power filtering, etc. For an antenna project, device protection may be critical. Don't ask how I know this. And if these are transmitting antennas, the relay logic might even be the best solution. I've seen a relatively low power transmitter drive a PLC nuts.

I would have to agree that a brick PLC would be best choice.

I am a big on the Rockwell Micrologix 1000. It has the input/output you are looking for and once in and running will probably never need to be looked at again except for troubleshooting external devices by using built in lights.

A very stable and reliable unit, with good programming tools.


John Caldwell

Why not use a Zelio Smart Relay by Schneider Electric. It is quite powerful and easy to use with free software. It accepts 24v logic signals and has relay or solid state outputs. It also accepts analog signals.